


O Deus Tenebrarum (Throne of the Demon Thief)

by Sharyrazade



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses, The Legend of Zelda & Related Fandoms, The Legend of Zelda: Twilight Princess
Genre: Bad Ending, Canon Dialogue, Choose Your Own Ending, Clairvoyance, Cross-Posted on FanFiction.Net, Cultural Differences, Emotional Manipulation, F/F, Fire Emblem: Three Houses Black Eagles Route Spoilers, Gen, Historical References, Hurt No Comfort, I Wrote This Instead of Sleeping, Mind Manipulation, Morally Ambiguous Character, Philosophy, Post-Black Eagles Route (Fire Emblem: Three Houses), Post-Canon, Power Imbalance, Pyromania, Religious Discussion, Sassy Ganondorf
Language: English
Status: Completed
Published: 2019-12-21
Updated: 2019-12-21
Packaged: 2021-02-26 02:46:41
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 6,033
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21656224
Author URL: https://archiveofourown.org/users/Sharyrazade/pseuds/Sharyrazade
Summary: She'd never been one to attribute any agency to vampires, specters, ghosts, or demons. There was power in this world, and that was all that mattered- all that SHOULD have mattered, anyway.However, the man slouching in the throne that was rightfully hers, with his odd, ashen skin, flame-red hair, and wicked grin on his pearly-white teeth honestly did give this man the image of a demon, contempt and amusement dripping from every syllable he uttered."Welcome to my castle."
Relationships: Edelgard von Hresvelg/My Unit | Byleth, Minor or Background Relationship(s)
Comments: 2
Kudos: 11





	O Deus Tenebrarum (Throne of the Demon Thief)

**Author's Note:**

  * Inspired by [Blood, Spirit, Hatred](https://archiveofourown.org/works/8907712) by [Sharyrazade](https://archiveofourown.org/users/Sharyrazade/pseuds/Sharyrazade). 



> Or alternatively titled: Byleth learns she's fucked. Along with the the rest of Fódlan and environs.  
> Or: Edelgard learns that, no matter how powerful you may be, there is in fact, always a bigger fish- like a Great White. And that perhaps chumming the waters is not such a great idea.

As grand as it was and as triumphant as their return to its halls should have been, there was something utterly...odd about the interior of Enbarr's grand palace, even to the point where it seemed completely devoid of life. Then again, given the massive military conflict that had (again) embroiled the continent, and the stormy night outside, this was not exactly a surprise.

"I-is this place h-haunted?!" inquired Bernadetta fearfully. "Please, please, please say no...!"

The emperor sighed in exasperation. "Bernadetta," began Edelgard. "there are no such things as ghosts, monsters, or demons."

"Of course!" remarked Ferdinand, seeming somehow distracted. "Our fair imperial palace is haunted by ignoble brutes alone!"

"Indeed. It is utterly humiliating to be driven from one's own capital."

How exactly it had begun was somewhat of a mystery. But perhaps one of the oddest parts of the whole rebellion was one of its leaders. Duke Apollonius had been one of Edelgard's foremost supporters in her campaign against the Church of Seiros for years now. In fact, it was not so much that he was anti-church, but anti-religion in general. No one thought it particularly odd once he became somewhat more secretive and reclusive a couple of years back. By the time anything had seemed amiss, Apollonius and a cadre of other nobles had already raised a massive army in rebellion against Enbarr. Understandably, Hubert, utterly humiliated by such an oversight, seemed even more sour than usual throughout the course of the year-old rebellion.

"Lady Edelgard," he began dutifully. "They have been disposed of. Those odd stonemasons continuing to build as the rebel dogs surrendered- the fools."

"Excellent." she replied. "But is it possible that the 'no quarter' directive has been somehow counterproductive?"

"Oh, no, perish the thought, milady! Such scum cannot be allowed draw breath a second longer than absolutely possible!"

The normally upbeat, cheerful Caspar huffed in a tone reminiscent of a man ordered to slay his childhood friends in battle and execute his own father afterward. "Well, let's just take the palace back so we can end this- hopefully."

Linhardt yawned. "Well, hopefully, you shouldn't have to wait much longer. Any entrances and exits are secure and we're here anyway."

Hubert pushing open those ancient-yet-immaculately-kept doors to the throne room, much like the remainder of the palace, was utterly abandoned save for the loyalist soldiers patrolling the lonely corridors. Yet, there was something...or someone...seated on the throne, much to Edelgard's fury.

She'd never been one to attribute any agency to vampires, specters, ghosts, or demons. There was power in this world, and that was all that mattered- all that SHOULD have mattered, anyway.

However, the man slouching in the throne that was rightfully hers, with his odd, ashen skin, flame-red hair, and wicked grin on his pearly-white teeth honestly did give this man the image of a demon, contempt and amusement dripping from every syllable he uttered.

"Welcome to my castle."

Undeterred, Edelgard stood tall, befitting her personality and one in her position. "You there!" she barked. "Identify yourself at once! For the sake of notifying your next of kin, more than anything- or the next ten of them for this trespass."

The man-demon's grin only widened at this display of impotent insistence of her authority, not unlike that of a Cheshire cat with an especially-defiant mouse trapped between its paws. "People call me many things; the Demon Thief, the Prince of Darkness, their deity, etcetera." he mused. "But I know who you are, Edelgard von Hresvelg. Or should I say, Flame Emperor? Or Empress of Fódlan? I am not terribly familiar with your parlance in this world, but I've been able to determine that all of them translate roughly to 'arrogant wench who has gotten herself far out of her depth."

The expressions of the queen's gathered warriors (save for her beloved teacher) twisted into expressions of shock and occasional outrage, murmuring among themselves in confusion.

Unflapped as ever, Edelgard, while wincing internally, continued her exchange with this intruder. "Prince of Darkness?' 'Deity?" she retorted. "All I see is a sad, out-of-his-mind middle-aged man unable to understand the gravity of his crimes. Not that it matters. You've mere hours before you're executed for them. And for what? Some sad devotion to delusions of godhood?"

At this, the man could no longer obscure his amusement with the situation, giving a spine-chilling, semi-demonic laugh. "Better beings- men and not- than you have tried, girl! They've all failed."

The second-most frightening man in the throne room bowed his head dutifully. "No need for that, Lady Edelgard. If you would allow me to dispose of this reprobate posthaste, that is."

If Edelgard may as well have been a rat trapped between the demon's paws, Hubert had the impact of a flea, at the very best. And the demon thief responded with an appropriate reaction- laughter. "And you've even less chance than this stupid wench, you arrogant, scheming, greasy-haired fop." he reminded. "I can appreciate a good curse just as much, probably more than the next man. But you? What with your plots and your poisons, and mindlessly following every depraved order she gives you like some smitten schoolboy, no matter how much blood they stain your hands with. And for what? Tell me, what do you really hope to gain?"

The demon thief reclined in the throne. "You are so utterly transparent, I can read you like a piece of poorly-written, stunted piece of supernatural semi-erotica for juveniles. Or juvenile minds, anyway."

As if to respond to these rather cutting accusations (or to begin casting), for whatever reason, Edelgard's right hand could not muster a vocal riposte to this taunt. The dutiful noble however, steadied his stance, dominant hand gripped on his lance as though it were some sort of comforter. "H-how dare you, ingrate!" stammered Ferdinand. "For every soul, common and noble alike, there are strict protocols for petitioning Her Majesty-"

The uninvited guest turned his terrifying gaze onto the dutiful noble. "You know, boy," he began smugly. "your private, traitorous thoughts are not nearly so private with me. And yes, I do agree. You WOULD make a better ruler than this queen of the ashes. But that is an abominably low bar, I admit. What fraction of your people have lost their lives because of her? A tenth? A sixth? A fourth? A third?"

As her scandalized retainers gasped and chattered, Edelgard trained her condemning visage on both the guest and Ferdinand alike. The next to challenge the demon, was perhaps unsurprising as he always was among the most headstrong, for better or for worse. "And just who the hell do you think you are?!" demanded Caspar, pointing his axe accusatorially. "You just waltz into our home- our continent- and set up like you own the place?!"

The thief gave a toothless, closed-mouth smirk. "Interesting words coming from warriors of the most bloodstained empire in your world's recent memory." he remarked. "But quite simply, I am the one with the power- the power of the gods, to be precise- therefore, my word is law to those with less power than I."

He turned his amused gaze onto a very-unamused Edelgard. "Surely, one such as you can appreciate the simplicity of such an arrangement. Why, I could even order a son to slay his father after battle in order to prove his loyalty to me!"

The normally-cheery warrior's expression turned noticeably downcast, very noticeably avoiding looking in Edelgard's direction "Father...why did you...?"

Dorothea simply scoffed in derision. "Wow, I've met some real pieces of work, but calling yourself a god?" she remarked harshly. "No wonder you'd rather bathe Fódlan in blood than give up your privileges to a woman whose boots you're not fit to clean- you nobleman pricks really are all alike, huh?"

The very-dominant "interrogatee" gave a laugh of genuine amusement. "Ha! Look down on you for being women?! On the contrary, I rather like this one here! This 'emperor' to whom I owe so much of my success in this world! I dare say, you would be in for a surprise if you learned who first taught me to track, hunt, fight, ride, cast spells, and hit a target from the back of a galloping stallion!"

Having little interest in their guest's recounting of an upbringing in a completely different world, let alone culture, one member of the party was more interested in his claims. "He's not calling himself a god _per se_ , Dorothea." remarked Linhardt. "He means he claims power like those of his gods. Omniscience- the ability to know everything- and what have you. But for a living, breathing human like you or I? It's physically impossible."

Said malicious guest bared his teeth in a very amused grin. "You should have followed your instincts and stayed in bed, boy." he remarked. "Alright, you disbelieve me? Your region of Hevring is known for earthquakes, is it not?"

Raising an eyebrow, Linhardt was unimpressed for now. "Yes..." he confirmed. "But that's a well-known fact. Not exactly secret knowledge."

"What about the quake three-and-a-half years ago that struck the capital region of your family's lands?"

"What about it?"

"The survivors first took notice off the tremors at exactly eight thirty-three in the morning. From there, aftershocks continued for exactly twelve hours. Not a second longer. One of the aftershocks that collapsed a number of mines in the northeast- and took your father and a couple thousand of his slaves- I'm sorry, your new countrymen- with them. In total, the fatalities totaled a good thirty-five thousand souls."

Linhardt literally felt his heart skip a beat at how precise these calculations were. Exact numbers were hard to come by, as he strongly suspected Edelgard to have sent Hubert on a tour of the region to "advise" the local nobles to keep quiet about such things, but to his knowledge, the figures given by the demon were very reasonable, if not probable. But how? If even he and fellow nobles lacked such precise information...how did this monster of a man have it?

"I know all this because I created the quake! So tell me, boy." the thief began with a grin. "How much blood _is_ on your hands exactly? Blood of combatants, blood of the innocent? It scarcely matters."

At this piercing question concerning one of his greatest fixations, Linhardt lacked an answer. Or lacked an answer that he liked, anyway. The gentle mage muttered to himself about how impossible this was as their guest was interrogated by another of the Black Eagles. "You have creating so much suffering!" accused Petra. "And what for? Your own amusement?! You are no warrior!"

The demon thief scoffed in contempt. "Spare me." he demanded, one wicked, golden eye focused on Edelgard. "You speak of what a noble warrior tradition your country has, yet you make no effort to lead your people away from this one's clutches."

"I-we believe in Edelgard and her idea." she protested, a slight twinge of doubt in her tone as she grasped her blade so hard her knuckles began to turn white.

At this, their guest seemed genuinely disgusted. "Don't pretend to be something you're not." he scolded harshly. "You're no warrior. You're nothing more than a chained bitch who lets this wench walk all over her people for a bone and a pat on the head every now and again."

Much like the others who received such a dressing-down, Petra seemed genuinely conflicted by the points made against her.

"I..."

Again, the demon bared his teeth in an amused grin. "And don't think you outsiders are any better just because you're not from this continent. Be sure to tell your dear grandfather that the Spirit of Vengeance personally sends his regards to the king of Brigid."

The reaction of the one very noticeably hiding herself behind Caspar's bulky frame was probably even less surprising than those of her liege, muttering " _there's no such thing as ghosts, monsters, or demons..."_ fearfully like a mantra as she quivered.

"Now that's just plain rude, girl! Telling someone they do not exist as they're speaking right to you! I've seen some things in my time and can personally testify- all three, are in fact, very, very real. Didn't your father and mother raise you better than that?"

One could almost sense a piece of Bernadetta's spirit dying from the demon merely glancing in her direction.

Stomping the heel of her boot impatiently against the tiling, Edelgard brandished her axe with a flourish. "Well, whatever you are, I tire of this charade." she remarked. "You all cannot seriously be unnerved by these petty mind games, can you? And even if he speaks the truth- a monster who claims to be a god- ha! You think it's outside our power to dispose of another one of you?"

"Ah, of course." he replied, most unimpressed. "Seiros, that pitiful woman. I suppose I can sympathize somewhat- being the last of one's kind is never anything but trying, after all. Then again, I have far better company than she ever did."

Clutching what appeared to be a staff in his left hand, the Great Thief rose from the throne at long last. Holding his right fist high, he revealed the presence of a golden, shimmering, triangular mark upon the back of his hand, just beneath his second and third knuckle. While neither Byleth, nor any of her erstwhile students said a word, all of them (with one noticeable exception) recoiled reflexively, as if some part of their being knew his claims were no jest.

After several seconds of the shimmering light dying down and the thief descending the steps like some sort of usurper monarch, Caspar finally spoke. "W-what the hell is that?"

Their guest's wicked smile returned. "Four very simple words." he began. "Power. Of. The. Gods. Shall I paint you simpletons a picture?"

At this boast, Edelgard simply scoffed. "Mere parlor tricks. You'd think me so simple to be impressed by this? I should have you executed for poor magic tricks alone!"

By now, the uninvited guest was rather visibly displeased by Edelgard- both by her steely facade and the lack of success of his psychological warfare. "Oh, get over yourself, wench. Words cannot describe how tired I am of you and your youthful hubris."

"Ha! Says the man who calls himself a god!"

"Well, when one gets to my age with my life experiences, you learn a thing or three about hubris- whether one likes it or not."

"Fine final words before I, in my authority as emperor, righteously cleave your head from your shoulders."

"Again, better beings than you have tried- and all failed."

The demon thief gave a sinister chuckle as he began to pace in front of the gathered crowd. "Such an overwhelming sense of impatient self-righteousness can only come from the young." he remarked. "The same as in every age, really."

"What are you babbling about now?" demanded Edelgard impatiently.

"What would you say if I told you about a noblewoman and her warrior whose devotion to one or more goddess was the source of much of their power? On both of their parts?"

Head tilted sideways in an ever-so-slight hint of confusion, Edelgard furrowed her brow. "I would call them a pair of charlatans of weak minds and morals using their 'piety' to add to their own legend and prey on the superstitions of the commoners."

"Oh, no, on the contrary- meddlesome, damnable, more tenacious than a colony of centenarian cockroaches- but never weak. And never insincere."

"Spare us the fairy tales- they'll do nothing to lighten your sentence, nor do they have any bearing on the situation here in the slightest."

Fodlan's most powerful uninvited guest allowed himself a sinister laugh before he continued. "So tell me, girl." the thief king began. "Why is it you suppose that literally every society to exist has developed some sort of religious idea and practice? Not merely rituals, beliefs, and worship either, but as a complete worldview and lifestyle as well. Why has this proven to be the case in every world I have observed? Why do the mountains and deep forests of Faerghus remain death traps for your soldiers? Why do many of the lords who've theoretically pledged their loyalty to you continue to shelter recusant churchmen and their pious relatives?"

Edelgard von Hresvelg had been accused of being many things, quite a few of them to her face. None of them however, could call into question just how sharp her mind was; she could see the ploy coming after the first question had concluded. "The same as in every age, really." she echoed scornfully. "Hypocritical, power-hungry clerics inciting them to act against their own best interests. Not to mention the common interest."

"Sometimes, yes, sometimes no. But is it possible that the content of the religious belief is secondary for most? Is it possible that that sense of kinship and solidarity is what is most attractive? The belief and participation in something greater than they could ever be?"

Edelgard scowled fiercely, knuckles whitening as her grip on Aymr tightened. "I've- We've done just that, you senile old fool! Reunited a continent and forged a nation, not with the use of superstition and unwarranted nobility, but through blood and iron!"

Judging by his great, bellowing laugh, the demon thief was extraordinarily amused by this level of ambition- if not hubris- almost to the point of being in tears of malicious joy. Edelgard was, of course, completely and blissfully unaware that she and her dear teacher had done the better portion of his work for him. "You truly and genuinely believe that this little project of yours can take the place of the gods- any gods- in the hearts and minds of your peoples?!" he inquired rhetorically. "Stupid girl! I have witnessed some strong delusions and hubris in my days, but you-?!"

Edelgard growled as her guest continued to laugh and ultimately collect himself. "I'm glad you see your very imminent, very public, and very painful execution as such a laughing manner." she threatened. "Care to explain what's so damned hilarious?"

"Oh, if you insist, 'Your Majesty.' As I said previously, peoples' religions- any religion- can be an extraordinary tool of motivation in the right hands."

"Or the wrong ones." insisted Edelgard.

The sorcerous thief ignored this little aside for the most part. "It scarcely matters. A tool of extraordinary motivation that they can and will cling to jealously, especially in times of trial and crisis."

Momentarily, the evil, golden-eyed glare was fixed again on Hubert, even he shirking at the dark lord's focus on him- wicked, self-satisfied smile and all. "Your friends who slither in the dark would know that VERY well." he reminded. "For millennia, their pride and anguish bled across the void and reached me. Their hatred of the gods and the surface dwellers was my nourishment- I drank deep of it and that same hatred allowed me to grow strong again, in time able escape the prison prepared for me and manifest in this world. And they were merely one lost civilization of equally lost souls. What exactly do you think I would be able to accomplish feeding from the fear, rage, despair, and hatred of an entire, blood-soaked continent, stripped of its ancestral religion? Well, you already have your answer, if you care to look for even a second."

His beady eyes momentarily widening like saucers, Hubert swore to himself. Given his intimate knowledge of the cult- his co-conspirators- and their guest's semi-omniscience (or at the very least, an impossibly-strong network of eyes and ears across the continent) concerning other matters, he, unlike his lady, privately had little reason to doubt at least some of his account. And this was only compounded upon by his demonstration of clairvoyance he'd practiced on von Aeigr and Linhardt. "Oh, by the way, boy." he resumed smugly. "My magic is such, that if you misplaced one of those tomes by dropping it literally right in front of your face and I willed it otherwise, even your children would never be able to find it as long as they lived. Or their children, or their grandchildren, or their great-grandchildren, and so on. I've hidden things vaster than cities from the eyes of those far more powerful than you."

Edelgard however, while still unimpressed, seemed to have been given a moment of pause by the depth of her guest's knowledge of perhaps the continent's darkest secret. "But you still have not answered the question of why the hell you're darkening the door of my throne room." she reminded, perhaps with a touch less hostility. "You must be one of Apollonius' conspirators, no other explanation makes any sense whatsoever. Still, this is quite some length to go for just for a bit of dramatic playacting. It's literal insanity."

"Heh, the Mad Queen lectures me about insanity." the thief retorted. "How utterly droll. For perhaps the tenth time tonight, girl; you completely misunderstand human nature, or simply see it as something that can be irrevocably altered through sheer willpower. Again, people's gods- or some equivalent thereof- are extraordinary tools of motivation. Be they called Sothis, Hylia, the Great Thief, the Dark Lord, the Spirit of Vengeance , the Great Stallion, or what have you. And unlike with your Duke Apollonius or your slithering friends, most of the time, I scarcely need to do anything! And that's not changing anytime soon- if ever. No matter how many of those priests and nuns you crucify, how many of their places of worship you destroy and replace with your monuments, how many of their artifacts and icons you force them to trample on pain of death, or how many recusants you turn into human torches."

Even for those who'd followed her through thick and thin, through quite a bit of bloodshed, such measures were controversial, to say the very least. Particularly Edelgard's (always denied) apparent fascination with immolation as an execution method. Even the razing of Garreg Mach ( _"Come now, my teacher. Can we REALLY afford to give our enemies a place of commemoration at F ódlan's exact geographical center?"_) as the site for a future capital, if for no other reason than the sentimental value, was met with an increasing level of concerned whispers.

"Forever is a long time, 'demon thief.' What proves true today and yesterday may be completely overturned tomorrow. And there are times where you must drag a child kicking and screaming into the future. This is one of those times; It's for their own good-"

Bobbing his head vertically as if in tone with his high-pitched, exaggerated impression, the dark lord cut her off. "It's for their own good,' 'It's for their own good." he semi-singsonged. "You know, you really need a new mantra, you foolish wench. So if I understand this correctly you, Edelgard von Hresvelg, with the aid of short-sighted and unscrupulous fools in your country, decide to invade and the neighbors and scour their lands, rip out the long-established religious order root and branch, completely remake society in your own image, enforce said edicts through blanket brutality and punitive, confiscatory taxation, and honestly expected most people, even after decades of 'normalization,' to go along? Essentially, you had to destroy the continent in order to 'save' it?"

Their guest bought his massive, ashen hands together in a slow, sardonic clap. "Truly, the Queen of the Ashes, this one! _Brava_ , _brava_ indeed!" he congratulated sarcastically. "Foxes everywhere await your further innovations in henhouse design!"

Having witnessed this back-and-forth between Edelgard and this demon thief, Byleth, as much as she adored her, could actually find little to fault the odd, sinister man as far as his arguments were concerned. Then again, she remained the one figure largely unscathed by his acerbic tongue up to that point, and this was not to last. "But out of everyone to whom I am indebted," the dark lord began, that familiar, sinister smile creeping across his lips. "I probably owe more to you more than anyone else."

Said smile quickly transitioned into his semi-maniacal, Cheshire cat-like grin, gesturing in the general direction of Edelgard with his implement. "It wasn't enough that you followed this piper and her tune off an everloving cliff, you managed to drag your entire damned world with you for the fall! As another example of your sterling judgement- not unlike a caravan's members all deciding they can do without extra water for a desert trek- you chose this girl and her hubris over the power of your own gods! I should have thought you'd have a decent sense of what kind of a wench you'd gotten involved with once she seemed a bit _too_ excited by the thought of burning these recusants to death for not recanting their religion. Oh, by the by, has that bite mark on your hindquarters healed yet, 'Professor?"

Byleth was honestly more disturbed than even Hubert and Linhardt at the depths of his knowledge, reflexively running her left hand over her backside before she felt her heart drop into her stomach, fearing whatever revelation the man of the desert was to deliver. "Again, we must refer to our friend Seiros," the thief resumed, the glee and anticipation in his tone barely disguised. "that pitiable, lonely soul whom I cannot shake the feeling of having met before in another world and time. Her efforts to create a vessel suitable for your world's goddess to enter into and act in this world required the consent of the soul in question, no? Yet you, 'Professor,' in all your infinite wisdom, gave up the power of your creator in favor of humanity, thereby removing that same suitability as a vessel for another spirit- that damnable, meddling, do-gooder spirit which is probably fated to dog me in every age- the only one capable of taking up the blade to strike me down!"

As he continued his exposition, the dark prince's expression transitioned from one of relative levity to one of unbridled fury directed at Byleth. "I can even SEE it in you, girl!" he declared. "That vacant body language, those empty blue eyes, that dumb, dopey, blank look, that STUPID-"

Clearing his throat, their guest's expression returned to its relatively pleased disposition. "But that is neither here nor there. My point is that you have made the worst possible chain of choices in following this-"

Perhaps it was this berating of her dear teacher that had set Edelgard off, but she had this time genuinely had enough. "I've indulged this lunacy long enough." declared Edelgard. "You die, now!"

Once again, those almost-unnaturally white teeth flashed in a grin. "Well, you're very welcome to try. It's been a while since I've had some firsthand excitement."

In spite of all her previous bluster, Edelgard did not have any reason to doubt the man to be extraordinarily powerful- just not in an otherworldly sense. To this end, she gestured to the retainers (accompanied by a rather judgemental glare at Ferdinand) for one of their formations- to attack the intruder more-or-less simultaneously. There was no possible way he could be standing- let alone breathing- after such an onslaught.

Caspar, Petra, and Ferdinand all attacking him from three separate directions, Hubert and Linhardt found their focus abruptly broken by a terrifying chain of sights. Apparently, their guest was not exaggerating his power. In fact, he was probably underselling it: Even without turning to face him, the intruder, blocked both Caspar's axe and Petra's blade with his bare fists and arms, picking up the latter and hurling her clear across the throne room as though she were a ragdoll wielding a twig before he bought his right knee up to block Ferdinand's own attempt to run him through, caving in his chest plate and sending him into one of the pillars. While his friends lived still as far as he could tell, Caspar was of course, horrified to see the demon manipulating and bending his axe as though it were soft clay, wrenching it from his hands and using his great size to pull him into his knee. He'd been in more of his share of scrapes, but the boisterous warrior found himself in such excruciating pain from the knee strike to the stomach, he credited the armor with his surviving at all.

The arrows the anxious archer had directed at the intruder proved less like deadly projectiles and more like feathers impacting against her enemy- when they connected at all, that is. Unfortunately for Bernadetta, the demon, despite his giant frame, was still agile enough to snatch two of the projectiles straight out of the air, snapping one of them two and hurling it into her leg with pinpoint accuracy. Unfortunately as well, her shrieks of pain were more-or-less inaudible to the others for the time being. Charging at him with a great cry of rage, Edelgard noticed something odd about the "staff" held in the demon's left hand. It was no staff at all, but a sheath for an almost-blindingly-luminous blade; however, as furiously as Edelgard and Byleth- without a doubt, the most powerful warriors there- attacked the demon, Linhardt noticed something odd about the clash. While the emperor and her beloved teacher were clearly swinging their weapons with all their might, the demon thief, seemed to be putting little, if any effort into parrying them and countering- and doing so as though he had centuries of practice. It would be admirable if one could not almost literally smell the sulfur wafting from his person, he thought. He _knew_ he should have stayed in bed, today of all days.

Edelgard struggling to remain standing against the man's literally inhuman strength, she nonetheless remained faithful to the oft-rehearsed plan. "Do it, now!" she commanded, she and her teacher both breaking off the engagement to give the demon a wide berth. At once, their intruder was enveloped in a pair of furious cyclones, one of pure darkness and another of ice and wind. And Dorothea, for good measure, sent a bolt of the scalding blue flame into the maelstrom from above. As the conflagration raged, Edelgard, while wearing a smirk of self-satisfaction, was privately relieved. No man could possibly survive such an onslaught!

To all of their horror (those not already distracted by their excruciating wounds anyway), the man proudly stepped forward from the unholy mass of magical energy, neither a scratch on his person nor a hair out of place. "That's...that's not possible!" Edelgard protested.

The demon thief smiled evilly, raising his right hand in which a sickly, purple counterpart to Dorothea's flame began to pool. "What did I tell you, girl?" he reminded, at once ejecting the flame at Linhardt and Dorothea, sending them both to the ground in just as much, if not more pain than their fellows. "Power of the gods."

"And you call that a spell, boy?" he inquired of an utterly-terrified Hubert. "Ha! My mothers put me through worse as a lad just to toughen me up! THIS is a spell!"

With a cry of rage, the thief raised his right in his direction, from it overwhelming, suffocating waves of darkness began to envelop the pallid sorcerer, the overbearing sense of darkness appearing to steal the breath straight from Hubert's lungs, collapsing onto his hands and knees as he began gasping and rasping for breath, even after the dissipation of said darkness.

Still able to move his neck despite the overwhelming pain from the invisible scalding across his body, Linhardt noticed something very interesting about the engagement. Given that he, Dorothea, and Hubert (the latter seeming on death's door already) received the worst injuries so far and that for all the fury with which Edelgard and the Professor continued to attack the demon with, he treated the attacks as little more than a nuisance. A game at the very worst. This was the source of two separate, but closely-related revelations; while perhaps not a god himself, the man clearly could claim to be blessed with their power. And perhaps even more horrifying was the fact that he was clearly toying with them all. He had been ever since they entered they entered the throne room, or even the city of Enbarr. That was the only logical explanation for him not having wiped them all from existence already. No matter what punishment or coercion Edelgard managed to threaten him or his family with, he _really_ should have stayed in bed today.

Byleth, quite fatigued herself, was only now getting a sense of the power with which she was dealing. Perhaps, if she could still call on the power of Sothis- no, it was far too late for such thoughts. Then again, exhausted as she was, she was still in a better state than her teacher's pet. Exhausted and her grip on Aymr already slipping, after one last parry, the demon effortlessly knocked the axe from Edelgard's grasp, sending it flying into the artificial canal and the woman to her knees from the force of the blow. "Ready to give up yet?" he taunted, pointing the blade at her neck. "Come now, you foolish girl! You've shed so much of your school chums' blood already. Do you really want to sacrifice the lives of this lot on a fight you've already lost?"

"Never." spat Edelgard defiantly. "I will NEVER surrender to the likes of you. No matter how many of their lives it costs me, even if it costs me my own! Even if I have to burn them and myself to ash to destroy you, I will."

"Ha! What an admission of refreshing honesty from you! You all hear what your emperor really thinks of her 'beloved' comrades?"

Animated purely by adrenaline and fury by this point, Edelgard did, in a life of questionable choices, something that was none too wise in simply charging the great thief to continue their battle unarmed. Unfortunately for her, she'd given little conscious thought to just how lightning-quick his reflexes were despite his great size, effortlessly grasping her exposed throat and lifting her well into the air. "I'm in something of a hurry," began the demon, turning to Byleth. "so I would like to conclude this rather quickly."

Byleth gasped at the prince of darkness tightening his grasp around Edelgard's throat. "What?!"

"I am seeking to access a world- you would necessarily have no knowledge of- known as the Sacred Realm. Unfortunately, for all my powers, it is extraordinarily well-protected, with only one point of access in the entire cosmos of which I'm aware. As that door has been literally closed to me, I require you to use what remains of your power to make another for me, Fell Star, and I will be on my way and release your dear student. I shall even lend you a bit of mine, if you so require."

Much of the congeniality drained from his expression as Edelgard continued struggling for breath, tightening his grip in response. "Or, I could end this little charade, snap her neck, and finish you all off. I'm certain you'll make the correct decision."

This man, this demon, whatever one wished to call him already had legions of fanatic followers in Fódlan and probably beyond. If he were to be unleashed upon the world, it would be an abject calamity! And besides, thought Byleth. She honestly did see how one could mistake his power for that of a god. While she could see even Edelgard's resolve fraying somewhat in her slightly-purpling visage, she was receiving quite mixed reactions.

_"Just give this freak what he wants so we can be done with this nightmare! Ow-"_

_"Don't do it, Professor! We can -ow- still take him!"_

_"Let's not...act too hastily..."_

_"Fight still...can I..."_

_"Another bad day...another bad day..."_

_"This kind of thing never happens in my room..."_

_"Lady Edelgard..."_

_-This decision will drastically change the story-_

_\- "Okay, I'll do it. Just don't hurt them any more." (Open a passage to this "Sacred Realm")_

_\- "Die, monster!" (Attack the Demon Thief to save Edelgard)_

**Author's Note:**

> Yes, I am very well aware that this is very much one of those big industrial vats calling the kettle black. But this was kind of a reference to one of my other big projects in the FE fandom. And I just needed to write the Prince of Darkness himself being smug and roasting Dany and Byleth like King's Landing for making it too easy for him. Since this was literally, canonically his ploy with Zant, I don't think some faceless Adrestian noble would be any more resistant to it than him. In fact, he'd probably be less resistant to it.

**Works inspired by this one:**

  * [Ignis et Sanguis (Idus Majorae)](https://archiveofourown.org/works/26765995) by [Sharyrazade](https://archiveofourown.org/users/Sharyrazade/pseuds/Sharyrazade)




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